F-15X: USAF Seems Interested

[element1loop]

The combat radius with payload, is a lot less than the ferry range, though. Much of the difference is due to routing. An F-15 won't fly the same route/altitude as an F-35, in combat (unless it's completely permissive airspace.)

And that's where the comparative range discussion becomes moot.

First, the F-35 can remain HIGH-HIGH-HIGH and maximize range and optimal altitudes, even under full internal load.

Second, the F-35's planning system is thus much more likely to produce a very fuel-efficient optimal routing plan (speed vs altitude, ISA, wind-modelling, AOA change, etc) which sips the least cruise fuel to obtain the desired TOT, given also that the clean cruise speeds will be much higher, and will probably descend and climb half as much as an F-15E is likely to need to do, on a different flight profile.

Third, the F-35 will not need (and will avoid using) A/B thrust, due its light internal load (compared to available payload) and its clean configuration. Plus there’s the need to reduce thermal signature and maintain stable aspect control.

The loaded F-15E does not have the ability to rule-out potentially protracted use of A/B so needs a much larger buffer to keep a reserve viable, thus reducing its practical combat range substantially, in high-threat areas. The F-15E will necessarily avoid penetration, so needs standoff (and its range will gain benefits) but needs supports, or else it's unable to participate until the area is made benign via F-35s efficiently penetrating and controlling it.

So stated range is not that comparable in practice, and once F-35A does its thing the tankers can come in closer and the range and external drag becomes less of a hindrance for both types.

But I think we can all see the potential for F-35A to much better manage its fuel flow in combat in that, and to go relatively further as a result of better fuel management options, unless those are also being pushed hard to maximize radius. And at the beginning of a fight they probably will be pushed hard ... so which jet do you want more of in there?

[weasel1962]

No disrespect but that's an A2G discussion. Legacy CAP at low levels only?

Wondering why the F-15C can't remain HIGH-HIGH-HIGH and maximize range and optimal altitudes also?

[element1loop]

No disrespect but that's an A2G discussion. Legacy CAP at low levels only?

Wondering why the F-15C can't remain HIGH-HIGH-HIGH and maximize range and optimal altitudes also?

Were you not both also discussing CFTs, bags plus LGBs and minor AAM loads, comparatively?

[h-bomb]

of course the F-15 has considerably more drag than the F-35. Yet with all the drag of carrying 2 CFTs and 3 tanks, it still reaches 3400nm.

Its a real testament of what PR means. Get a pilot to say the F-35A is magic plane and voila...hook, line, sinker.

Unfortunately for the rest of us, the drag index of a AIM-120 on an F-15 is 1.7 on a CFT station, 2.3 on a wing station and 2.1 for an AIM-9. That has a major impact, all of less than 1% on the range. For comparison, the CFT drag number is 20.1 or a 600 gal tank is 12.2.

Not per the USAF:
Range: 2,400 miles (3,840 kilometers) ferry range with conformal fuel tanks and three external fuel tanks
https://www.af.mil/About-Us/Fact-Sheets ... ike-eagle/

But they are just posting PR BS here:
https://www.af.mil/About-Us/Fact-Sheets ... htning-ii/

[weasel1962]

No disrespect but that's an A2G discussion. Legacy CAP at low levels only?

Wondering why the F-15C can't remain HIGH-HIGH-HIGH and maximize range and optimal altitudes also?

Were you not both also discussing CFTs and LGBs and minor AAM loads?

F-15C w LGBs? Which air force?

[weasel1962]

Not per the USAF:
Range: 2,400 miles (3,840 kilometers) ferry range with conformal fuel tanks and three external fuel tanks
https://www.af.mil/About-Us/Fact-Sheets ... ike-eagle/

But they are just posting PR BS here:
https://www.af.mil/About-Us/Fact-Sheets ... htning-ii/

Strike eagle. See earlier link also by USAF for F-15Cs. Having to do a lot of reposting continuously so apologies if I just do a referral.

[element1loop]

Wondering why the F-15C can't remain HIGH-HIGH-HIGH and maximize range and optimal altitudes also?

And why would one want an F-15C CAP, when you can have and F-35A CAP? Six BVR missiles with VLO, EOTS and DAS not going to cut it?

The justification has to be for the F-15C to exist in service at all. And also to justify some imaginary need to obtain an F-15X (in any numbers) with CFT on the basis of A2A and AAM numbers 'advantage'. The F-15X would need all those weapons just to put the other guy off their game, and be lucky to get kills and survive.

But the F-35A is able to engage closer unseen, auto-organize a multi-axis ambush unseen, and fire weapons in numbers and timing sufficient to decimate an opposing flight quickly, from different directions unseen, and the remnant, if there is one, still has no SA. So are they sticking around or prosecuting anything at that point? So are more AAMs needed? Or are just more F-35As needed?

[element1loop]

No disrespect but that's an A2G discussion. Legacy CAP at low levels only?

Wondering why the F-15C can't remain HIGH-HIGH-HIGH and maximize range and optimal altitudes also?

Were you not both also discussing CFTs and LGBs and minor AAM loads?

F-15C w LGBs? Which air force?

This was part of the discussion:

viewtopic.php?p=408362#p408362

[weasel1962]

Hell, I totally agree. F-35A is a better plane, no doubt and that's the plane I'd take for CAP vs a F-15C (or X) if I was a pilot.

Just don't like people denigrating a legacy unfairly just to sell more planes. The F-15 flies further. That's a simple fact by virtue of the crazy fuel loads it carries. Doesn't make the F-35 a lesser plane.

[element1loop]

Hell, I totally agree. F-35A is a better plane, no doubt and that's the plane I'd take for CAP vs a F-15C (or X) if I was a pilot.

Just don't like people denigrating a legacy unfairly just to sell more planes. The F-15 flies further. That's a simple fact by virtue of the crazy fuel loads it carries. Doesn't make the F-35 a lesser plane.

An F-15E can theoretically fly further due crazy fuel loads, but not necessarily in practice in combat from here.

The C is much more doubtful and the A2A-capability-only is not a great reason to keep it around (and you would hope an F-15X is much more useful than that).

[weasel1962]

Agreed but I see it more as a F-15C vs F-16C/D rather than vs F-35. The F-35A buys are accelerating so the all legacy sqns will be earmarked for replacement. Its just a question of which goes first. Some people might call it a happy choice having to choose between an F-16C/D or an F-15C on which gets moved first since whichever remains is still a fantastic aircraft.

The argument for keeping the C is that the -16, which a good multi-fighter would still lack against the capabilities offered by the APG-82s and all the other bells and whistles of the F-15C. The alternative is using the F-35A in the A2A role. I don't see a right or wrong answer here.

[Corsair1963]

Hell, I totally agree. F-35A is a better plane, no doubt and that's the plane I'd take for CAP vs a F-15C (or X) if I was a pilot.

Just don't like people denigrating a legacy unfairly just to sell more planes. The F-15 flies further. That's a simple fact by virtue of the crazy fuel loads it carries. Doesn't make the F-35 a lesser plane.

LOL

HELLO, the F-15 doesn't fly further.......Yet, feel free to go tell Lt. Col. Scott “CAP” Gunn (USAF), the Commander of the 33rd Operational Support Squadron at Eglin AFB, FL and Lt. Col. Christine Mau (USAF), Deputy Commander of 33rd Fighter Wing Operations Group also from Eglin AFB. Which, are both ex Eagle Drivers. (F-15C and F-15E respectively) That you "know" more than them.......

[weasel1962]

I don't claim to know more than pilots. Just stating facts which are supported by USAF, manufacturer data, a lot of F-35 presentations that show combat range and a simple explanation reconciling what the pilots stated to the data. Still haven't read anything that is contradictory.

What however is clearly debunked is that the F-35A is way better in every conceivable role the F-15 can do which is not the case nor what the pilots have suggested (which you appear to say "supports" your stance).

Just wanted to state that I'm not the first to claim the other party is crazy which is what you have just done (same as in the past). So run along and complain to the mods again.......that's incredibly christian...

[element1loop]

Agreed but I see it more as a F-15C vs F-16C/D rather than vs F-35. The F-35A buys are accelerating so the all legacy sqns will be earmarked for replacement. Its just a question of which goes first. Some people might call it a happy choice having to choose between an F-16C/D or an F-15C on which gets moved first since whichever remains is still a fantastic aircraft.

The argument for keeping the C is that the -16, which a good multi-fighter would still lack against the capabilities offered by the APG-82s and all the other bells and whistles of the F-15C. The alternative is using the F-35A in the A2A role. I don't see a right or wrong answer here.

I do. The F-16C/D will become second-tier ground attacker and perhaps escort/cover for support aircraft, which slows and complicates for an opponent until F-22A gets there.

F-22A and F-35A/B/C are the real deal from here and F-35 can provide data to make the F-16C/D and the F-15E actually useful sooner in a fight to use the legacy A2G, but they can't make the F-15C very useful in A2A, except in a lower threat situation, which the F-15C is still more or less not needed for anyway ... if the F-35A/B/C and F-22A are around.

So the F-16C/D is clearly a more desirable choice to keep longer, and according to guys like Gums they don't lack for range when loaded.

I appreciate your points Weasel, but I think you have this wrong when it comes to the in-practice implications.

[Corsair1963]

I don't claim to know more than pilots. Just stating facts which are supported by USAF, manufacturer data, a lot of F-35 presentations that show combat range and a simple explanation reconciling what the pilots stated to the data. Still haven't read anything that is contradictory.

What however is clearly debunked is that the F-35A is way better in every conceivable role the F-15 can do which is not the case nor what the pilots have suggested (which you appear to say "supports" your stance).

Just wanted to state that I'm not the first to claim the other party is crazy which is what you have just done (same as in the past). So run along and complain to the mods again.......

Sorry, that your online sources aren't supported by people that have direct knowledge and actual experience with the F-15C/E and F-35A. Yet, what do they know.......